The instant invention relates to an improved dual-tone electronic music generator which provides a phase difference (2ms) between the melody and the chord. This permits both the melody codes and the chord codes, which are respectively converted from the original melody and chord, to be loaded into a common memory in series. Such an arrangement can increase the memory usage efficiency, and can reduce both the chip size and the production cost.
Referring to FIG. 1, the conventional dual-tone electronic music generator mainly comprises a pair of melody memory (10) and chord memory (11) which are associated with control circuits so the melody and the chord can be arranged to be synchronous with each other. However, since the number of notes for each of the melody and the chord of a music usually are different from each other, it is difficult to simultaneously select the desired melody from these two memories (10) and (11). In addition, as soon as one of the memories (10) and (11) are filled with codes, the other memory can no longer be utilized. Therefore, the aforesaid memories can not be adequately utilized. In an alternative configuration, the said two memories (10) and (11) can be combined into a single memory and the two address counters (12) and (13) can be combined into a single address counter. Although such an arrangement may reduce one address counter, the actual memories used therein are still the same. If one attempts to reduce the bits of the memory in order to save the hardware size, the chord codes, stored in said memory will be reduced accordingly, However, this may adversely affect the quality of the composed melody.
It is, therefore, an object of the present invention to obviate and mitigate the aforesaid drawbacks.